Heat exchangers used in motor vehicle air conditioning systems condensers commonly have a plurality of parallel flat sided extruded tubes connected at opposite ends to a pair of headered tanks, and air centers connected between the tubes to facilitate efficient heat transfer to the surrounding area. The headered tanks generally comprise a separate header with slots therethrough for receiving the extruded tubes, and a tank secured to the header to supply refrigerant and receive the same from the tubes. The air centers are brazed to the sides of adjacent tubes, and the tubes are brazed or otherwise bonded to the header along with the tanks to assure leak free joints.
During assembly, the header and tanks must be secured to one another so that brazing can seal the joints therebetween. It has been known to align and fasten the tanks to the header by use of self-contained, preformed tabs spaced at intervals about the periphery of the header or tank as disclosed in U.S. Pat. No. 4,971,145, issued Nov. 20, 1990 in the name of Lyon and issued to the assignee of the subject invention. The preformed tabs are clinched over the adjoining part to provide proper alignment between the mating tank and header, and also provide appropriate contact pressure to facilitate the joining or brazing process. This tab assembly method increases the depth of the tank to header joint geometry since additional space is required to accommodate for the integral clinched tabs. The dimension penalty can cause space packaging problems in certain vehicle applications. In addition, providing the self-contained tabs also requires considerable additional raw material size for the tab containing components.
U.S. Pat. No. 4,738,308, issued Apr. 19, 1988 in the name of Moranne discloses a mechanical assembled heat exchanger of similar type described above. The heat exchanger forms the headers to the tanks by providing side flanges connected at either end of the tank units to clamp the ends of the header plate to the tank, in conjunction with spacers or side plates which are connected between the tank units.